A method of managing a multi-level memory device having singularly addressable three-level cells includes storing strings of three bits by coding them in corresponding ternary strings according to a coding scheme and writing each of the ternary strings in a respective pair of three-level cells. Strings of three bits are read by reading respective ternary strings written in respective pairs of three-level cells and decoding each read ternary string in a corresponding string of three bits according to the coding scheme. A pair of adjacent bits, belonging to at least one of a same initial string and two initial adjacent strings, are programmed by identifying pairs of three-level cells to be programmed that encode the strings of three bits and programming each pair of three-level cells.